I understand what you mean about the mods and higher rpm power vs stock, Fred and procharged. I have never hit the limiter and I know I've gone past 5500 close to 6000 before. I'm pretty sure I had Solomon at lt1pcmtuning raise it to 6k. I guess you're right about the 0-60 concept since no drag ever ends at 60. I will reconsider your advice on the 4.10 vs 3.90. Any guess what 1/4 mile improvements I'm likely to see with either 3.90 or 4.10s? My car is very healthy and I use strictly AC Delco replacement parts.

 

Are you using the stock tach to determine the RPM? If so, it typically reads 100-200 RPM higher than actual RPM. When my car was basically stock, I could rev it to 6,000 RPM on the stock tach, with the stock rev limiter settings. But using a scanner, I realized I wasn't really at 6,000 RPM. If you are shifting at 5,500 on the tach, you may actually be shifting at 5,300.

My tach shows yellow from around 5,200-5,600 RPM, with the red area starting at about 5,700 RPM.

 

not trying to hijack but gotta question. i cant afford a 12 bolt or 9" and do the current mods im trying to do so what options are there if any to beef up the stock rear end?

 

nevermind i see the sticky at the top

 

Read this.... $1,700 later it was still limited to 450HP with an A4, and not recommended for the M6.

http://highperformancepontiac.automo...ild/index.html

http://www.highperformancepontiac.co...ild/index.html

 

this is interesting....never knew our tachs were high by 100-200